The Sign Of The Four: Summary

 The Story begins with Sherlock addressing his need for some case to keep his brain working, without which he is a drug addict. Soon at their door arrives Miss Marry Morstan with a charming attire, which seduces Watson somewhat. Marry explains her case to Sherlock which is about her father, Captain Morstan who was deployed in India ten years ago. Morstan came back to London and called upon for Marry, but when she arrived at his lodge, Morstan had gone missing. She tried to search for him everywhere, also contacting his only acquaintance in town- Captain Sholto who was deployed in India along with him. Sholto declined any knowledge of Morstan's missing. Four years later, Mary saw an advertisement in the newspaper with someone looking for her address. Marry gave her address after which she started receiving a very expensive pearl, each year on the same day. The sender being unknown never contacted Mary in the past six years when until now he had sent a letter for a meetup, where the person claimed to provide Mary with some justice she deserved.

Sherlock takes in some documents that Mary provided her, along with a map that shows a hall, and the names of four people- Jonathan Small, Dost Akbar, Mahomet Singh, and Abdullah Khan, signed as The Sign Of The Four. Sherlock ignores this particular document as being irrelevant to the case but keeps it for future reference. He investigates Captain Sholto, who has been dead for the past six years and Mary receives the first pearl only after one week of his death, which somehow appears to be a strange chronology for Sherlock. Sherlock devises a plot, where he holds Sholto responsible for Morstan's death, after which his children started sending a pearl to Mary as compensation, but now, this sender claims to provide some sort of justice to her. In the mentioned time, Mary, Sherlock, and Watson gather to travel to their destination when they finally arrive at the residence of Thadeus Sholto, the son of Captain Sholto. Thadeus recites the entire truth.

Ten years ago, Captain Sholto arrived back with an enormous fortune from India, which was a treasure he collected from India. Sholto and Morstan had an equal claim on the treasure when they broke into an argument and during the heat of it, Morstan got killed accidentally. Lal Rao, the housekeeper helped Sholto hide the body, and since then Sholto pretended to have no knowledge of Morstan's disappearance. After some time, Sholto received a letter that left him in a state of melancholy, after which his health slowly started to decrease. Once he even shot a random man with a wooden leg out of fear which was later compromised. Before his death, Sholto explained the entire mystery to his twin sons Bartholomew and Thadeus about the treasure being in the Pondicherry Lodge. After his death, his room had been raided by someone who left a piece of paper, inscribed with the text- The Sign Of The Four. Before his death, Sholto had also ordered his sons to help Mary Morstan by giving equal part in the treasure or wealth, as she is also the rightful owner of it. Since then the Sholto brothers had been sending a pearl to Mary and had been looking for the treasure. Bartholomew just the previous day had found the treasure in an upper vault of the Pondicherry lodge, and they would now divide the treasure equally among themselves.

On arriving at Pondicherry Lodge, Sherlock, Watson, Mary, and Thadeus find Bartholomew dead, with a piece of paper, inscribed with the text- 'The Sign of the four'. Thadeus decides to contact the police before he is seen as the culprit of the case, as Thadeus is the last person Bartholomew meets in the room. Inspector Athenley Jones arrests Thadeus after making his false theory. Sherlock investigates the entire room and finds a dart in the neck of Bartholomew, which had been shot from a hole in the ceiling, which Bartholomew had made to fetch the treasure hidden in it. Sherlock and Watson enter the vault through the hole in the ceiling and find small footsteps such as those of a child. Also, Sherlock finds footsteps on the shelf of the window of the room and finds out that a man with one wooden leg has entered. He deduces that the man in charge of this murder is Jonathan Small, as in the document which contained names of all the four members, only one was British, and Captain Sholto earlier had shot someone mistakenly, and that person was also a British statesman. Sherlock figures out that there were two men who did this murder. One of them came in through the ceiling and shot Bartholomew and then helped the other one with a rope to climb up to the window. 

Watson and Holmes then use Toby, a dog to lead through a scent in the crime scene. Toby leads them to a wharf, from where the criminals had taken a steam launch (a boat) called Aurora and escaped. Holmes spreads out his street Arabs in search of Aurora and waits. After an ordeal of not finding the boat anywhere, he finally spreads the false information that he had stopped looking for the boat when the criminals finally reveal themself at the bank of Thames. Holmes disguises himself as an old man to receive a tip from Wiggins that the boat has been found. With the help of Athenley Jones, who has now learned that Thadeus was not responsible for the murder of his own brother, they set out on a journey to confront the criminals.

In a chase sequence in River Thames, they find out Jonathan Small, accompanied by a dwarf from Andaman Island who tries to kill them, but eventually is shot. Small is finally captured and confronted, when he reveals that the key and treasure have been thrown into the river itself, and the box now lies empty. He reveals that years ago, he got retired after serving in India when he started working at a farm. Soon there was an attack by Indian soldiers, when a bunch of them sought asylum at Agra fort. There he met the other three members who were natives and told them about a treasure being brought by a merchant named Achmet. Achmet was slaughtered by the four ruthlessly and his treasure was hidden by them in the fort itself. Soon the four were held guilty of Achmet's murder, and Jonathan was sent into exile in Andaman Island. On Andaman, he met Captain Morstan and Sholto to whom he told about the treasure, and made them agree to help him escape so that they can be a part of the treasure as well. 

Seduced by the idea of treasure, Morstan and Sholto robbed the treasure by themselves and fled away. Small learned about this betrayal when he escaped with a native of Andaman to find the treasure by himself. One of his friends in London gave him the entire news about things happening in the Pondicherry Lodge when Small started to keep an eye on the house. And since Bartholomew found the treasure, they decided to rob and flee away.

Watson reveals the empty box to Mary and finally is able to propose his love to her, to which she reciprocates. Meanwhile, Sherlock reveals that Lal Rao was the man who used to provide information to Jonathan Small.